This pedal is much more useful than you might expect:
The saturation / compression side allows for everything from a slight harmonic boost to a full overdrive. As an added bonus, it can act as a clean boost using the output level control. I leave it on and dial the saturation between slight and high depending on the tone I want.
The tape delay side gives lovely single delay effects, but can also produce flange and chorus as well as a very fast slapback delay, all by changing the offset between the two virtual tape decks. A wobble control introduces a bit of random noise, so you can use this to just subtly thicken your sound, or as a full on delay pedal (only a single delay, but often that's enough).
Build quality is what you'd expect at this price, it's worth noting that you'll need a decent high current power supply if you're adding this to a board, I was trying to run this and an Eventide H9 off a Voodoo labs ISO5 and it can't do both - if you don't give enough juice you get an unpleasant hum from the Deco.
This is the only pedal I'll take to jam sessions, it can make pretty much any amp come alive (and I've played on some real shockers), and the option to put a time related effect on, quickly and easily, is fantastic. So, simple on first appearance, but capable of a lot of very powerful sound enhancement.